Marthasville is a city in Warren County, Missouri, United States. The population was 837 at the 2000 census. The Katy Trail, a 225 mile long bike path, passes through Marthasville, and the original grave of Daniel Boone is located there. In 1845, Boone's remains were disinterred and moved to Kentucky for burial. Resentment in Missouri about the disinterment grew over the years, and a legend arose that Boone's remains never left Missouri. Because of the many wineries from here east to Defiance, Marthasville is considered to mark one end of the "Missouri Weinstrasse".